Fuel injection mechanism for internal combustion engines



. H. D. BUSH. FUEL INJECTION MECHANISM FOR INTERNAL COMBUSTION ENGINES.

1,35 ,049 Patented Aug. 2,1921.

2 SHEETS-SHEET I.

APPLICATION FILED IAN. 30' I920.

H. D. BUSH. ECHANISM FOR INTERNAL COMBUSTION ENGINES. APPLICATION FILED JAN. 30, 1920.

FUEL lNJETION M Inventor Patented Aug. 2, 1921.

.UNITED STATES PATENT OFFICE.

HAROLD DAVID BUSH, OF GREENHITHE, KENT, ENGLAND, ASSIGNOR T0 HERBERT MERTON, OF READING, ENGLAND.

FUEL-INJECTION MECHANISM FOR INTERN AIL-COMBUSTION ENGINES.

Application filed January 30, 1920. Serial No.

To all whom it may concern.

e it known that I, HAROLD DAVID BUSH, a subject of the King of England, residing at Greenhithe, Kent, England, have invented certain new and useful Improvements in Fuel-Injection Mechanism for I nternal-Combustion Engines, of which the following is a specification.

his invention is for improvements in or relating to fuel-injection mechanism for internal-combustion engines of the type in which a pump is used to inject the fuel directly into the cylinder. lVhen such an engine is to be arranged to run in either direction two cams may be provided, one for running in either direction, the cams being spaced angularly apart so as to give the correct timing for the injection according to the direction of running, and means are provided for rendering either cam operative.

he reversal of an engine of this type, when running, is effected by injecting a charge of fuel very early in the compression stroke so that the ignition and combustion of the fuel is completed duringsuch stroke. One or more of such charges ultimately effects the reversal in direction of rotation of the engine.

In such engines moreover it is customary to vary the power and speed of the engine, by limiting the outward or suction stroke of the pump or pumps so that the inward.

or delivery-stroke duced.

Usually the pump is spring-controlled, so that the cam imparts to the plunger its delivery-stroke. while the spring effects the return-stroke when permitted to do so by another portion of the cam. For simplicity, the portion of the cam which effects the delivery-stroke of the pump will be referred to as the front face, and the other portion of the cam which permits the suction-stroke of the pump will be referred to as the rear face of the cam. It will be understood, however, that in some cases the rear face of the cam may be directly operative and not merely permit the operation of the pumpplunger by the spring. ccording to this invention a fuel-injection mechanism of the type above described for internal-combustion engines is characterized by both the cams for forward and reverse running being fixed rotationally with is correspondingly re- Specifieation of Letters Patent.

Patented Aug. 2, 1921. 355,045.

respect to the cam shaft, and the rear face of each cam beingso positioned that when erative, rear face of that cam 0perates on the pump to inject a reversing charge and bring about reversal of the direction of rotation of the engine.

Accordingto another feature of the invention, there is provided in a mechanism adapted forhand and governor control, the combination with a pump, its operating cams, and a lever interposed between them, of co-axial rotatable cams, one hand-operated and one governor-operated, each adapted to rock the lever out from enagement with the pump-operating cams, and means operated simultaneously with the hand-operated cam for selectively rendering operative a pump-0perating cam for one or other direction of rotation.

Other features of the invention relate to an improved construction and arrangement of fuel-injection mechanism and its controlling gear as hereinafter described.

In the accompanying drawings which illustrate one embodiment of the present invention Figure 1 is a longitudinal vertical section on the line 1-1 of Fig. 2 of the fuel-injection mechanism and its controlling gear for a four-cylinder engine.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Figs. 3 and 4 are the mechanism.

ike reference characters indicate like parts throughout the drawings.

Referring first to Figs. 1 and 2, the engine is provided with a suitablecasing or frame 10 which may be formed with or attached to the engine bed-plate in any desired manner. Upon the sides of this casing there are mounted a plurality of fuel pumps indicated at 11 and 12 respectively in Fig. 2. In the preferred construction one fuel-pump is allocated to each cylinder of the engine and in the present instance four of such pumps are provided to servea four-cylinder engine.

The pumps are all arranged to lie in the same horizontal plane and have their plungers 13, 14 directed toward one another. The main cam-shaft 15 lies also in the same part views of details of horizontal plane and carries cams for operating the pumps. Four cams 16, 17, 18 and 19 are shown i Fig. 1 and they are formed on or mounted on a sleeve 20 which is rotatable with the cam-shaft 15' but is movable longitudinally thereon. The camshaft is driven by a gear-wheel 21 from the engine crank-shaft by any suitable gearing.

The cams are arranged in pairs 16, 17 and 18, 19 respectively, one cam of each pair being for forward running and the other cam for reverse running. Only four cams are provided although there are four pumps, because the pumps are arranged in pairs 13, 14 in the same transverse plane so that a cam operates one pump and then, 180 later, operates the other pump, these two pumps being allocated respectively to cylinders whose cranks are 180 apart. If the pumps were not set apart 180 relatively to the cam-shaft, or if the engine cranks were not similarly arranged it would be necessary to have two cams for each pump.

The pump-operating cams above mentioned do not bear directly uponthe pumpplungers, but rocking tappet levers are interposed between them, one lever for each pump. As shown. most clearly in Fig. 2 these levers take the form of bell-cranks 22, 23 pivoted re slpectively on suitable brackets at 24, 25. he lower ends of these levers carry suitably journaled rollers 26 upon which the operating cam bears and the rear face of the lever bears directly on the end of the pump-plunger.

The'upper ends of the bell-crank levers 22, 23 overlap one another and in order to render the whole mechanism compact, the overlapping ends are reduced in width as shown most clearly in Fig. 1 at 27,. 28, the part 27 being an extension of the lever 22 and the part 28 a similar extension of the lever 23.

A control-shaft 30 is mounted in the same vertical plane as the cam-shaft 15, and above it. This shaft 30 has freely mounted upon it a sleeve 31 rotatable through gearing 32 by the controlling-handle 33; the sleeve has formed or secured upon it a hand-control cam 34. There is also mounted freely upon the shaft a governor-controlled cam 35 which is shown more clearly in Fig. 3. This cam is provided with a gear-wheel 36 engaged by a curved rack 37 which is fast upon a shaft 38. This shaft 38 is adapted to be rocked through a lever 39, link 40 and lever 41 by a centrifugal governor indicated in Figs. 1 and 2 by the general reference character 42.

The shaft 38 has loosely mounted upon it a sleeve 43 carrying an arm 44 upon the end of which is formed a thrust-member 45. This thrust-member, as shown in Fi 1, extends across all the overlapping en s of the bell-cranks 22, 23, and is so positioned that it can. be engaged on its upper side by the hand-control cam 34 or the governorcontrolled cam 35.

The control-shaft 30 also has mounted upon it a stepped-cam 46 which is rotatable with the shaft and hand-control cam 34. This cam 46 engages a spherical end 47 on a rocking lever 48 pivoted in suitable brackets 49 on the casing 10. The lower end of this lever engages in. any suitable manner the main-operating-cam-sleeve 20. so as to move it longitudinally when the steppedcam 46 is turned.

The thrust-member 45 is provided at one end with a tooth or projection 50 shown in Figs. 1 and 4 which is adapted to be engaged by a lug or detent 51 on .a sleeve 52 which is free to turn on the control-shaft 30 or the sleeve 31. The sleeve 52 is provided with a control-spring 53, as shown in Fig. 4, tending to turn it anti-clockwise in that figure. The sleeve 52 also carries a second arm 54 wherein an adjustable abutment 55 is mounted to engage an arm 56 fast on the shaft 38 which is rocked by the governor 42. The arrangement issuch that when the engine speed falls the consequent movement of the governor causes the shaft 38 to be rotated, in Fig. 4, in an anti-clockwise direction so that the arm 56 causes the sleeve 52 to be rotated against the action of the spring 53 in a clockwise direction in Fig. 4.

The operation of this mechanism will now be described. v

With the parts in. the position illustrated, the hand-control cam34 has depressed the thrust-member 45 (see Fig. 2) to the full extent and the bell-crank levers 22, 23 have thereby rocked on their pivots so as to carry the rollers 26 out from engagement with the main operating cam 18. Assume now that the engine is running ahead; the cam 34 has been turned by the controlling handle 33 so as to allow the bell-crank levers 22, 23 to swing in and engage the operating cams. Assuming that the cam-shaft 15 is turning in the direction indicated by the arrow in Fig. 2, the front face f of the cam 19 is about to engage the roller 26 on the lever 22 to operate the fuel-pump 11 to inject a charge into its cylinder. It will be appreciated that the angular setting of the cam'19 on the crank-shaft is such in relation to the crank angle for that cylinder that such injection takes place at the desired point on the stroke. Similarly the rear face 1' of the cam 19 is about to permit the plunger 14 of the injection-pump 12 to make its suction stroke.

\Vhile the engine is running in this way if the speed rises to an excessive amount the governor, operating through the rack 37, turns the cam 35 (Fig. 3) so as to engage the thrust-member 45 and depress the overlapping ends of the bell-crank levers. The

ength of their suction stroke and of the livery stroke is thereby reduced and smaller charges are supplied to the cylinders so that less power is developed and the speed of the engine falls.

Also the speed of the engine can be controlled in a similar manner by the hand-control cam 34 being turned more or less to depress the thrust-member 45 and thereby restrict the rocking motion of the levers 22, 23 to any desired extent.

f now it is desired to reverse the direction of rotation of the engine, the controllever 33 is moved from the ahead position through the neutral to the reverse position. In so doing the rotation of the shaft 30 carries with it the stepped-cam 46 and the step isarranged to pass the ball 47 at the neutral position of the handle, so that when the handle moves into the reverse position the cam-sleeve 20 has been shifted longitudinally so as to bring the reverse-cam 18 into the position previously occupied by the cam 19, that is to say into line with the rollers 26 on the levers 22, 23. Th

is running in the opposite direction. But the engine has not yet reversed although the cam 18 has been brought into action. The rear face R of this cam, which faces in the same direction as the front face f of the cam 19 and is therefore virtually a front face for this direction of the rotation, is so positioned that it operates on the pumps to inject the required charge very early in he compression stroke and thereby ultimately to effect reversal of rotation of the engine in the well-known manner. As soon as the rotation is reversed the said rear face R becomes in fact the rear face of the cam and the fuel injection is effected by the front face F which is so positioned as to give the correct timing for normal running. The manual and governor controls of the speed of the engine when running in the reverse direction are exactly similar to those above described.

In order to prevent undue stresses being developed by an injection of reversing charges of fuel while the engine is rotating at a high speed, the mechanism illustrated in Fig. 4 is'used. \Vhen the engine is stationary the arm 56 has turned sufficiently far in an anti-clockwise direction to turn the sleeve 52 in a clockwise direction and carry its projection 51 clear of the projection 50 on the thrust-member 45 so that the said projection 50 rides up on the righthand side of-the projection 51 and holds the sleeve 52 from turning under the influence of the spring 53. This state of affairs continues during normal running although the deth arm 56 will have been moved clockwise by e governor clear of the abutment 55. When however reversal is to beeffected the hand-control cam 34 depresses the thrust-member 45 to its full extent and this is sufficient to permit the projection 51 (see Fig. 4) to clear the projection 50 and spring into the position indicated in Fig. 4. It thereby holds the thrust-member 45 fully depressed even although the controlling-handle, and the main cam 34. are moved still further into the reversing position. As soon as the thrust-member 45 is held down the supply of fuel is completely cutoff and the speed of the engine thereby falls. When it reaches a predetermined low value the lever 56, under the operation of the governor, rocks the sleeve 52 in a clockwise direction (see Fig. 4) and carries the projection 51 clear of the projection 50 and thereby releases the thrust-member 45 allowing it to rise so that the bell-crank levers are free to be engaged by their operating cams. reversing injection of fuel is then commenced and the operation of the engine continues normallyas above described.

It will be appreciated that the mechanism hereinbefore described gives a very simple and compact construction of injection mech anism and controlling gear therefor for an internal-combustion engine. i

arious modifications may be made in the precise details of construction. Thus for example instead of using one pump for each cylinder and two cams to operate each pump, it would be possible to use two separate pumps for each cylinder, one for each direction of rotation. Inthis arrangement it would not be necessary to shift the operating cams to render one or other operative, as the pump which it is desired not to operate could be held out of action by depressing its bell-crank lever. That -is to say, instead of a single hand-control cam 34 there would be a pluralityof such cams so spaced pumps for each cylinder thereby rendering either or both pumps inoperative. These and other modifications are all held to lie within the scope of the present invention although the construction above described and illustrated is the preferred one.

What I claim as my invention and desire to secure by Letters atent is In an internal-combustion engine of the kind wherein reversal is effected by producing a counter-explosion in the cylinder, the combination of a fuel-injection pump for injecting fuel directly into the cylinder, a cam-shaft arranged to be driven by the engine, two cams displaced angularly relatively to one another, one for forward and one for reverse running, rotatable with said The ' to operate said thrust character described,

' scribed.

' char e into the cylinder cams when cam-shaft, and means for bringing either of said cams into and out of operative relation with said pump, cam being so positioned angularly that when the engine is running in one direction and the cam for running in the reverse direction is rendered operative, the said rear face of that cam operates on the said pump to inject a reversing charge into the cylinder to bring about reversal of the direction of rotation of the engine, substantially as described. v

2. In an internal combustion engine of the character described, the combination with a fuel-injection pump, of a cam-shaft arranged to be driven b the engine, two cams, one for forward an ning, rotatable withsaid cam-shaft, a tappet-lever having one arm co-acting with said pump, means for bringing either 0 said cams into and out of operative relation with said arm of the tappet-lever to operate said pump, the rear face of each cam being so positioned angularly that when the engine is running in one direction and the cam for running in the reverse direction is rendered operative, the said rear face of that cam operates on the said arm of the lever to inject a reversing charge into the cylinder to bring about reversal of the direction of rotation of the engine, a thrust member engaging said lever and arranged to rock the same out of and into operative engagement with both of said cams when the latter are in operative positional relation therewith, governor-controlled means arranged member, and manually controlled means arranged to operate said thrust member independently of said governor-controlled means, substantially as de- 3. In an internal combustion engine of the the combination with a fuel injection pump, of a cam-shaft arranged to be driven by the engine, two cams, one for forward and one for reverse running, rotatable withsaid camshaft, a tappet-lever having one arm co-acting with said pump, manually operated means for bringing either of said cams 1nto and out of operative relation with said arm to operate said pump, the rear face of each cam being so positioned angularly that when the engine is running in one direction and the cam for running in the reverse direction is rendered operative, the said rear face of that cam operates on the said lever and pump to inject a reversing to bring about reversal of the direction of, rotation of the engine, a thrust member engaging said lever and arranged to rock the same out of and into operative engagement with both of said the latter are in operative positional relation therewith, governor-controlled means arranged to operate said thrust the rear face of each one for-reverse runmember, and a member operatively connected with said manually operated means and arranged to operate said thrust member independently of said governor -controlled means, substantially as described.

4. In a fuel-injection mechanism for an internal-combustion-engine, the combination of a pump, a pipe connection therefrom to the cylinder it is to supply, a cam-shaft driven from the engine, forward and reverse-running cams rotatively fixed on said shaft and each having its rear face so positioned angularly that when the engine is running in one direction and the cam for reverse running is rendered operative, the said rear face operates on a pump to inject a reversing change to bring about reversal of the direction of rotation of the engine, a bell-crank tappet-lever engaging said pump by one arm, a thrust-member engaging the other arm of said bell-crank tappetlever, and coaxial rotatable cams, one operated by a governor-controlled device, the other operated by engage of a pump, a pi e connection therefrom to the cylinder it is to supply, a cam-sha driven from the engine, forward and reverse-running cams rotatively fixed on said shaft and each having its rear face so positioned angularly that when the engine is running in one direction and the cam for reverse running is rendered operative, the said rear face operates on a pump to inject a reversing charge to bring about reversal of the direction of rotation of the engine, a

'tappet-lever engaging said pump, hand-controlled means engaging said tappet-lever' to rock it away from engagement with a cam, a spring-controlled detent adapted to engage and hold said lever when moved into its disengaged position, governor-controlled means operative on said detent to withdraw it when the en inc-speed has fallen to a predetermined vaIue, and means for selectively moving said cams into position to engage said tappet-lever.

6. In a fuel-injection mechanism for a multi-cylinder internal-combnstien engine of the type described, the combination of a cam-shaft, a plurality of fuel-injection pumps, one for-each cylinder, sides of the cam-shaft, a cam-sleeve carrying a pair of cams for each pump, rotatable with but movable longitudinally on the camshaft to bring either cam of a pair opposite its pump, said cams each having its rear 180 on opposite face so positioned angularly that when the engine isrunning in one direction and the cam for reverse running is rendered operative, said rear face operates on a pump to inject a reversing charge and. bring about reversal of the direction of rotation of the engine, bell-crank levers pivoted on opposite sides of the cam-shaft, each having one end engaging a pump-plunger and its other end overlapping the corresponding end or ends of the oppositely disposed lever or levers, a thrust-member parallel with the cam-shaft and bridging all the overlapping ends of the levers, a control-shaft also parallel Withthe cam-shaft, a hand-operated cam operating cams, a spring-controlled detent also mounted on the control-shaft and adapted to engage the said thrust-member when it has been moved to its full extent by the hand-operated cam, and a governor-controlled lever engaging said detent to rock it and release the thrust-member when the speed has fallen to a pre-determined value.

In testimony whereof I aflix' my signature.

' HAROLD DAVID BUSH. 

